The invention discloses arylacridine derivatives synthesized under palladium catalysis and a preparation method thereof. The arylacridine derivatives are prepared through a reaction with 2-(arylamino)benzonitrile derivatives and aryl boric acid as reactants. According to the invention, the reactants are wide in source; preparation is easy; the arylacridine derivative is low in cost and toxicity and difficultly affects human health; the reaction is carried out in a solvent which is water; during the reaction, a palladium catalyst, an additive and a ligand are also added into the solvent, wherein the palladium catalyst is any one selected from the group consisting of palladium chloride, palladium acetate, palladium trifluoroacetate and palladium acetylacetonate, and the additive is methanesulfonic acid; a reaction temperature is 90-110 DEG C, and reaction time is 20-25 h; and the whole reaction is carried out in air, the reaction conditions are very mild, easy to realize and safe, and the health of experimenters is guaranteed. The highest yield of the method can reach 94%; a series of the arylacridine derivatives can be prepared; and the method has high substrate universality and isworthy of popularization.